source of truth

Definition

The source of truth is a trusted data source that gives a complete picture of the data object as a whole.
Source: LinkedIN.

KERI and ACDC context

Source of a particular piece of information from one place, considered to present the truth. However both KERI and ACDC only commit to the secure attribution of who said something and not whether what has been said is true or not. Veracity is an individual (organisational) conclusion that needs governance and virtual credentials. KERI and ACDC support veracity (concluding it's the "the truth") but doesn't solve it.
Compound description by @henkvancann from sources: 1, 2

Truth

Truth is the property of being in accord with fact or reality. In everyday language, truth is typically ascribed to things that aim to represent reality
Source: Wikipedia.